溶胶-凝胶法改性碳纤维增强纳米HA复合材料的制备及性能研究

Study on Preparation and Properties of Nano-HA Composites Reinforced by Carbon Fibers after Modified by Sol-gel Method

先对碳纤维进行对氨基苯甲酸预处理,然后通过溶胶-凝胶技术在预处理后碳纤维表面涂覆HA涂层,随后利用粉末冶金技术制备改性碳纤维增强纳米HA复合材料。研究碳纤维的改性工艺,观察改性后碳纤维表面的微观形貌,测量不同碳纤维含量下复合材料的抗弯强度和断裂韧性。结果表明对氨基苯甲酸处理后碳纤维表面形成大量的纵向凹槽,表面粗糙度增加,将其在HA溶胶中提拉5次后可以在表面获得一层致密的、结合性能较好的膜层。烧结产物中HA过渡层可以很好地连接基体和碳纤维,提高纳米HA复合材料的力学性能,当碳纤维含量为3vol%时,溶胶-凝胶改性碳纤维/纳米HA复合材料的抗弯强度达到最大值84.6 MPa,是基体抗弯强度的3.45倍。当碳纤维含量为4vol%时,溶胶-凝胶改性碳纤维/纳米HA复合材料的断裂韧度达到最大值1.92 MPa·m1/2,是基体断裂韧度的2.43倍。

The carbon fibers disposed with p-aminobenzoic acid were coated with HA layers using sol-gel method. The nano-HA composites were reinforced by modified C-fibers using power metallurgy method. The mechanical properties of the nano-HA composites at the different C-fiber contents were measured. The results show that there are a lot of portrait flutes on the surface of the C-fibers after modified by disposal with p-amino benzoic acid. The surface of the modified C-fibers has high roughness. After dip in the HA sol for 5 times, the surface of C-fibers have a compact and fastness HA layer. HA layer on the carbon fibers of sintered compacts can better contact the carbon fibers and HA matrix to improve the mechanical properties of the composites. When the content of C-fibers is 3vo1% and 4vo1%, the sol-gel modified C-fibers/HA composites have the highest bending strength of 84.6 MPa and flexural toughness of 1.92 MPa · m1/2, which are 3.45 times and 2.43 times as high as those of the HA matrix,